Co(II) complexes loaded into metal-organic frameworks as efficient heterogeneous catalysts for aerobic epoxidation of olefins
Co(II) complexes loaded into metal-organic frameworks as efficient heterogeneous catalysts for aerobic epoxidation of olefins
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DOI：
10.1039/c5cy01099c
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发表时间：
2016-01-01
影响因子：
5
通讯作者：
Wang, Ge
中科院分区：
文献类型：
--
作者：
Wang, Jingjing;Yang, Mu;Wang, Ge
一系列高效的钴（II）锚定Cr-MOF（Cr-MIL-101-NH 2）催化剂，如Co（II）@Cr-MIL-101-Sal、Co（II）@Cr-MIL-101-P2 I和Co（II）@Cr-MIL-101-P3 I，已通过一锅法成功合成用水杨醛修饰末端氨基，吡啶-2-醛或吡啶-3-醛和将Co（II）离子锚定到中孔Cr-MOF载体中。Co（II）@Cr-MIL-101-P2 I催化剂对以空气为氧化剂的烯烃环氧化反应表现出高的催化性能，这是由于吡啶环上的氮原子作为强吸电子取代基，Co（II）物种的高分散性和高比表面积使基底与活性中心之间充分接触。Co（II）@Cr-MIL-101-P2 I催化剂中Co（II）离子与螯合基团之间的强配位作用保证了优异的循环性能。此外，所合成的Co（II）@Cr-MIL-101-P2 I催化剂实现了其对各种烯烃的普遍适用性，例如环状烯烃、三取代烯烃、脂肪族烯烃和芳香族烯烃。
A series of efficient cobalt(II)-anchored Cr-MOF (Cr-MIL-101-NH2) catalysts, such as Co(II)@Cr-MIL-101-Sal, Co(II)@Cr-MIL-101-P2I and Co(II)@Cr-MIL-101-P3I, have been successfully synthesized by one-pot modification of the terminal amino group with salicylaldehyde, pyridine-2-aldehyde or pyridine-3-aldehyde and anchoring of Co(II) ions into the mesoporous Cr-MOF supports. The Co(II)@Cr-MIL-101-P2I catalyst exhibited high catalytic performance for epoxidation of olefins with air as an oxidant due to the nitrogen atom in the pyridine ring as a strong electron-withdrawing substituent, high dispersion of Co(II) species and high surface area for sufficient contact between the substrate and active sites. The strong coordination interaction between the Co(II) ions and chelating groups in the Co(II)@Cr-MIL-101-P2I catalyst guaranteed the excellent recycling performance. Furthermore, the synthesized Co(II)@Cr-MIL-101-P2I catalyst realized its general applicability towards various olefins, such as cyclic olefins, tri-substituted olefins, aliphatic olefins and aromatic olefins.